Messages in this thread | | | Date | Thu, 9 Jun 2016 14:27:19 -0500 | From | Andy Gross <> | Subject | Re: [PATCH v3] tty:serial:msm:Do not restore Rx interrupts in DMA |
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On Tue, Jun 07, 2016 at 03:58:41PM +0530, Charanya Venkatraman wrote: > Avoid data corruption issues that result in CRC errors during file > transfers over serial ports at higher baud rates. > > The current msm_serial driver masks the FIFO Rx interrupts in > msm_start_rx_dma() since Rx FIFO interrupts are not required in DMA > mode. However, msm_complete_rx_dma() re-enables the Rx FIFO interrupts > which could cause RXSTALE event to be processed when a TXLEV interrupt > occurs. > > The following is the sequence of events that could occur resulting in > data corruption. > > msm_start_rx_dma -> msm_complete_rx_dma --> > spin_unlock_irqrestore(&port->lock) --> > msm_uart_irq()(For TXLEV interrupt) --> msm_handle_rx_dm() (Read from > FIFO resulting in data corruption) > > The patch fixes the issue by not restoring the RXLEV and RXSTALE > interrupts in msm_complete_rx_dma(). These interrupts are required only > in FIFO mode. > > Signed-off-by: Charanya Venkatraman <charanya@codeaurora.org>
Acked-by: Andy Gross <andy.gross@linaro.org>
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